Our goal is to dissect the mechanism by which kinetochore proteins binds the centromeric chromatin in the genome and creates the basis for a functional centromere. Since the project started by new postdoctoral associate in 2010, this work is in progress. A separate study was conducted in collaboration with a human pluripotent cell (hPSC) investigator Amander Clark (UCLA), where we discovered that the centromeric protein reserve plays a role in cell differentiation and in chromosome damage sensing. This work was published in Human Mol. Genetics August 2010. The follow up project was suspended due to the recent ruling on the use of hPSC in federally funded projects. We have followed up on this project using senescent human cells wherein we find that CENP-A appears to remain active despite the lack of cell cycle activity. We are now investigating, if, like in cancer cells (Gill et al, in review; and Ambartyasuman et al 2010), CENP-A plays an ectopic role in these cells.